Method for improving rotating bending fatigue performance of locomotive axle steel

A bending fatigue and wheel axle technology is applied in the field of metal material surface nanometerization, which can solve the problems of difficulty in meeting the requirements of fatigue performance, high surface roughness value of materials, and limited range of refinement, and achieves improved surface finish and simple realization form. , the effect is obvious

CN105441651AActive Publication Date: 2016-03-30INST OF METAL RESEARCH - CHINESE ACAD OF SCI
9 Cites 6 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2016-03-30

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The present invention discloses a method for improving rotating bending fatigue performance of locomotive axle steel, and belongs to the technical field of metal material surface nanocrystallization. The method uses surface mechanical rolling treatment technology for surface nanocrystallization of locomotive axle LZ50 steel, and the treatment process is performed on a numerical control surface nanocrystallization treatment system. After the surface nanocrystallization treatment, a LZ50 steel surface structure is transformed into a gradient nano structure, the outermost layer crystal grain size is 10-50nm, the grain size gradually increases with the increase of the layer depth to the original grain size; the LZ50 steel surface nanocrystallization treatment state surface hardness is in a gradient distribution state, the outermost layer microhardness value is greater than 3.0GPa, and is significantly improved compared with the matrix hardness value; and the LZ50 steel surface nanocrystallization treatment state surface roughness is less than 0.4mum, and is significantly improved compared with the turning sate surface roughness. The rotating bending fatigue performance of the locomotive axle LZ50 steel is significantly improved by the surface nanocrystallization treatment.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to the technical field of surface nanometerization of metal materials, in particular to a method for improving the rotational bending fatigue performance of locomotive wheel axle steel. Background technique

[0002] As one of the most important components in the running process of rail vehicles, the quality and service performance of locomotive axles are directly related to the safety of rail vehicles. The locomotive wheel axle is mainly affected by the rotating and bending load during service, and fatigue damage induced by fatigue cracks is very likely to occur. If the wheel axle fatigue fracture occurs during the operation of the locomotive and vehicle, it will inevitably cause serious accidents such as train derailment or even rollover. Therefore, improving the fatigue performance of the locomotive axle is of great significance to the safe operation of rolling stock. The current rail vehicle industry generally adopts increasin...

Examples

Embodiment 1

[0036] The locomotive axle steel is a medium-carbon alloy steel of the brand LZ50, and its chemical composition is (wt.%): C0.47%, Si0.17%, Mn0.6%, S0.03%, P0.03%, Cr0.03 %, Ni0.03%, Cu0.25%, Al0.02%, Fe balance. The initial delivery state of LZ50 steel is twice normalized + once tempered. The microstructure of LZ50 steel supply state is as follows: figure 2 As shown, it can be seen from the figure that the microstructure of LZ50 steel is mainly composed of ferrite and pearlite. The dimensions of LZ50 steel standard rotating bending fatigue specimens are as follows: image 3 shown. The surface nano-processing method of the present invention is used to process the fatigue sample of the locomotive wheel axle LZ50 medium carbon alloy steel. The WC-Co hard alloy ball diameter of the processing cutter head is 8mm, and the cooling lubricating liquid is selected CastrolCN008 / 04 type. image 3 shown. The selection of surface nano-treatment process parameters is as follows:

[0...